1. Field of the Invention
The present invention relates to an automated periodic surveillance testing method and apparatus in a digital reactor protection system, and more particularly, to an automated periodic surveillance testing method and apparatus in a digital reactor protection system, which unites a passive testing means such as a self-diagnosis or an on-line state comparison with an active testing means such as an automatic logic test and the like in the digital reactor protection system.
2. Description of the Related Art
A reactor projection system performs a function of protecting a nuclear reactor, so that a nuclear power plant is maintained in a safe state and radiation and radioactive substances are not leaked to an exterior of the nuclear power plant even when an accident occurs in the nuclear power plant. Therefore, the reactor projection system is a system that plays the most important role in the safety and reliability of the nuclear power plant.
Accordingly, the reactor protection system periodically performs a surveillance test with respect to safety-related functions based on the periodic surveillance test period (typically, 31 days) specified in the operation manual. Generally, in a periodic surveillance test, one of multiple channels (four channels) is rerouted (hereinafter, detoured), the test for the detoured channel is performed. When the test for the one channel is completed, the detoured state is cancelled, and the test is identically performed for another channel.
However, the periodic surveillance testing method in the reactor protection system may cause economical loss due to excessive time consumption and errors due to tests performed by people. For example, in the case of Uljin nuclear power plants 5 and 6 that employ a digital reactor protection system, the time consumed in a periodic surveillance test of the digital reactor protection system is about five days per nuclear power plant.
The time consumed in the periodic surveillance test of the digital reactor protection system is five times longer than the time consumed in a periodic surveillance test of an analog reactor protection system, which is about one day. Therefore, the advantage of an automatic test function performed by the digital reactor protection system is not used and is more deteriorated as compared with the analog reactor protection system. The time consumed in the periodic surveillance test of the digital reactor protection system is long since a digital reactor protection system has a more complex structure than the analog reactor protection system, the number of test items is greatly increased.
Therefore, a testing apparatus and method in a digital reactor protection system, which minimizes time consumed in a periodic surveillance test and automates tests and diagnostic means including a self-diagnosis, an on-line state diagnosis, an automatic logic test, and the like, is desired.